Tremors and Agitation Following Low-Dose Intravenous Hydromorphone Administration in a Patient with Kidney

Hydromorphone is a semisyntheticopi oid derived from the naturally oc-curring phenanthrene opiate morphine by the addition of a 6-keto group and a hy-drogenated double bond at the 7-8 posi-tion.1,2 Both morphine and hydromor-phone are metabolized in the liver by glu-curonidation at the 3-position to form their respective 3-O-glucuronide metabolites.2,3 Unlike morphine, hydromorphone has a ketone group at the 6-position that blocks direct glucuronidation at this site, resulting in the formation of 1 major metabolite, hy-dromorphone-3-glucuronide.2,3 The metabolism of morphine results in the formation of morphine-3-glucuronide (55%), morphine-6-glucuronide (10%), and normorphine (4%), among others, which are subsequently excreted via an active mechanism in the kidneys.4 The clearance of the parent compound is not affected by kidney dysfunction, but th